Bug 276936 - ixgbe: if interface is in bridge, and vlan interface on same interface is also in bridge, packets are not passed correctly
Summary: ixgbe: if interface is in bridge, and vlan interface on same interface is als...
Status: New
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: 14.0-RELEASE
Hardware: Any Any
: --- Affects Some People
Assignee: freebsd-net (Nobody)
URL:
Keywords: IntelNetworking
Depends on:
Blocks:
 
Reported: 2024-02-10 08:37 UTC by Lexi Winter
Modified: 2024-08-31 11:49 UTC (History)
1 user (show)

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Description Lexi Winter freebsd_triage 2024-02-10 08:37:45 UTC 
tested on: FreeBSD hemlock.eden.le-fay.org 14.0-RELEASE-p4 FreeBSD 14.0-RELEASE-p4 #8 releng/14.0-n265400-4edf3b80733e: Sat Feb 10 07:13:23 GMT 2024     root@hemlock.eden.le-fay.org:/data/src/obj/data/src/releng/14.0/amd64.amd64/sys/HEMLOCK amd64

sample broken configuration:

# ifconfig tap0 create
# ifconfig tap1 create
# ifconfig bridge0 create addm ix1 addm tap0 up
# ifconfig ix1.107 create vlan 107 vlandev ix0
# ifconfig bridge1 create addm ix1.107 addm tap1 up

although this config appears to work, the bridge1 interface will not pass packets correctly, and a VM attached to tap1 will have no network connectivity.  a VM attached to tap0 (on bridge) works fine.

this configuration works correctly, when both bridges use tagged interfaces:

# ifconfig tap0 create
# ifconfig tap1 create
# ifconfig ix1.106 create vlan 106 vlandev ix0
# ifconfig bridge0 create addm ix1.106 addm tap0 up
# ifconfig ix1.107 create vlan 107 vlandev ix0
# ifconfig bridge1 create addm ix1.107 addm tap1 up

i've only tested this with an ixgbe(4), so it may be specific to this hardware, but disabling all VLAN-related hardware acceleration with ifconfig did not fix the problem.

ix1: <Intel(R) X520 82599ES (SFI/SFP+)> port 0xe000-0xe01f mem 0xfb680000-0xfb6fffff,0xfbc00000-0xfbc03fff irq 55 at device 0.1 on pci10

# ifconfig ix1
ix1: flags=1008943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
options=4e53fbb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,WOL_UCAST,WOL_MCAST,WOL_MAGIC,VLAN_HWFILTER,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
	ether 90:e2:ba:1a:e1:15
	inet6 fe80::92e2:baff:fe1a:e115%ix1 prefixlen 64 scopeid 0x3
	media: Ethernet autoselect (10Gbase-Twinax <full-duplex,rxpause,txpause>)
	status: active
	nd6 options=1<PERFORMNUD>

there are several other people who have run into this issue, for example:
- https://github.com/churchers/vm-bhyve/issues/390#issuecomment-785537662
- https://genneko.github.io/playing-with-bsd/networking/freebsd-vlan/#do-not-bridge-the-parent-interface-of-the-vlans

maybe related to (or a dupe of) bug 240106.
Comment 1 Lexi Winter freebsd_triage 2024-02-10 08:41:31 UTC 
# ifconfig ix1.107 create vlan 107 vlandev ix0

this, and the other references to "ix0" in the original report, should have said ix1 instead:

# ifconfig ix1.107 create vlan 107 vlandev ix1

ix0 is not involved in test case, only ix1.